package com.bite.forum.interceptor;

import com.bite.forum.config.AppConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@Component
public class LoginInterceptor implements HandlerInterceptor {

    //配置项引用
    @Value("${forum.login.url}")
    private String defaultUrl;

    /**
     * 前置处理（预处理）
     * @return true: 继续流程 <br/> false : 流程中断
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //获取session 对象
        HttpSession session = request.getSession(false);
        //判断session是否有效
        if (session != null && session.getAttribute(AppConfig.USER_SESSION) != null){
            //用户已登录，校验通过
            return true;
        }
        //校验URL是否正确
        if (!defaultUrl.startsWith("/")){
            defaultUrl="/"+defaultUrl;
        }
        //校验不通过，跳转到登录界面
        response.sendRedirect(defaultUrl);
        //中断流程
        return false;


    }
}
